In a heterogeneous network, small access nodes (e.g., short range, low power access nodes) can be deployed at hotspots of a macro access node (e.g., strongest signal strength) to offload traffic and increase network system capacity. This allows a wireless device to be served by an access node having the lowest signal path loss rather than the strongest signal strength, as in traditional network configurations. In some instances, interference can occur at a cell edge of the small access node due to the reference signal strength of the macro access node. The macro access node may use inter-cell interference coordination techniques to consolidate wireless spectrum and frequency bands so that subframes of the wireless spectrum are “free” for allocation to the small access nodes.
Inter-cell interference coordination techniques, for example, designating subframes of the wireless spectrum as almost blank subframes (ABS), create opportunities for wireless devices operating at cell edges of small access nodes to receive downlink information from the network without interference from the macro access node. For example, scheduled transmissions from the macro access node may be minimized during the designated ABS. This reduces interference and degradation of performance of wireless devices served by the small access node, but can undesirably limit the amount of network resources allocated to wireless devices served by the macro access node during the designated subframes.
Overview
Systems and methods are described for scheduling traffic in an almost blank subframe (ABS) in a wireless communication network. In one instance, data transmissions to a wireless device in communication with a first access node may be scheduled during an ABS that is scheduled by a second access node. At least one wireless device that meets a criteria may be selected from a plurality of wireless devices in communication with the second access node. Data from the second access node transmitted may be transmitted to the selected wireless device during the scheduled ABS using beamforming.